Fluid pump providing balanced input/output flow rate

Abstract

A fluid pump device includes an elastically deformable conduit, multiple volume displacement elements, and a controller. During operation, the controller controls movement of the multiple volume displacement elements (such as compensation volume displacement elements and occluding volume displacement elements) with respect to the elastically deformable conduit at different times to cause flow of fluid in the elastically deformable conduit downstream to a recipient. The controller controls movement of the multiple volume displacement elements to volumetrically balance: i) an input flow rate of input fluid conveyed from a fluid source downstream to an input of the elastically deformable conduit, and ii) an output flow rate of output fluid delivered from an output of the elastically deformable conduit downstream to a recipient.

We claim: 
     
       1. A system comprising:
 an elastically deformable conduit; 
 multiple volume displacement elements to contact the elastically deformable conduit and displace fluid in the elastically deformable conduit, the multiple volume displacement elements disposed between an input port and an output port of the elastically deformable conduit; and 
 a controller to control movement of the multiple volume displacement elements, the controller volumetrically balancing: i) an input flow rate of input fluid conveyed from a fluid source into the input port of the elastically deformable conduit, and ii) an output flow rate of output fluid delivered from the output port of the elastically deformable conduit to a recipient; and 
 wherein the controlled movement equalizes the output flow rate and the input flow rate; 
 wherein the multiple volume displacement elements controlled by the controller include: first displacement elements and second displacement elements disposed between the input port and the output port; 
 wherein the second displacement elements include a first compensation displacement element and a second compensation displacement element; 
 wherein the first displacement elements include a first volume displacement element, a second volume displacement element, and a third volume displacement element; 
 wherein the second volume displacement element is disposed between the first volume displacement element and the third volume displacement element; 
 wherein the first displacement elements are disposed between the first compensation displacement element and the second compensation displacement element; 
 wherein the first compensation displacement element is disposed between the input port and the first volume displacement element; 
 wherein the second compensation displacement element is disposed between the third volume displacement element and the output port; 
 wherein the first displacement elements are controlled by the controller to occlude fluid flow through the elastically deformable conduit at different times during a delivery cycle to deliver the output fluid downstream from the output port of the elastically deformable conduit to the recipient; and 
 wherein the second displacement elements including the first compensation displacement element and the second compensation displacement element are controlled by the controller at multiple different non-blocking positional settings to provide fluid flow compensation for the first displacement elements. 
 
     
     
       2. The system as in  claim 1 , wherein the input flow rate and the output flow rate are substantially constant and greater than zero. 
     
     
       3. The system as in  claim 1 , wherein the movement of the multiple volume displacement elements results in: i) constant uni-directional flow of the input fluid into the input port of the elastically deformable conduit, and ii) constant uni-directional flow of the output fluid from the output port of the elastically deformable conduit to the recipient. 
     
     
       4. The system as in  claim 1 , wherein controlled movement of the multiple volume displacement elements prevents a backflow of the input fluid received at the input port of the elastically deformable fluid toward the fluid source. 
     
     
       5. The system as in  claim 1 ,
 wherein the controller is operable to:
 while the second volume displacement element occludes fluid flow through the elastically deformable conduit, control movement of the first volume displacement element to draw the input fluid downstream from the fluid source into the input port of the elastically deformable conduit. 
 
 
     
     
       6. The system as in  claim 1 ,
 wherein the controller is operable to, while the second volume displacement element occludes fluid flow through the elastically deformable conduit, simultaneously control movement of the first volume displacement element and the third volume displacement element in opposite displacement directions to convey the output fluid downstream from the output port of the elastically deformable conduit to the recipient at a desired flow rate. 
 
     
     
       7. The system as in  claim 1 ,
 wherein the controller is operable to, while the first volume displacement element occludes fluid flow through the elastically deformable conduit, control movement of the second volume displacement element and the third volume displacement element in opposite displacement directions to convey the output fluid downstream from the output port of the elastically deformable conduit to the recipient at a desired flow rate. 
 
     
     
       8. The system as in  claim 1 ,
 wherein the controller is operable to:
 while the second volume displacement element occludes fluid flow through the elastically deformable conduit: i) control movement of the third volume displacement element to convey the output fluid downstream from the output port of the elastically deformable conduit to the recipient, and ii) control movement of the first volume displacement element to draw the input fluid downstream from the fluid source into the input port of the elastically deformable conduit. 
 
 
     
     
       9. The system as in  claim 1 , wherein the multiple volume displacement elements:
 are controlled by the controller to occlude fluid flow through the elastically deformable conduit at different times during a delivery cycle to deliver the output fluid downstream from the output port of the elastically deformable conduit to the recipient. 
 
     
     
       10. The system as in  claim 1 , wherein the fluid source is a first chamber of a diaphragm pump, the controller operable to measure a volume of a second chamber of the diaphragm pump to determine a flow rate of the input fluid delivered to the input port of the elastically deformable conduit. 
     
     
       11. The system as in  claim 1 , wherein the input flow rate and the output flow rate are continuously equal during an entirety of each of multiple repetitive control cycles of controlling the multiple volume displacement elements. 
     
     
       12. The system as in  claim 11 , wherein the input flow rate and the output flow rate are set to a fixed flow rate value during an entirety of each of the multiple repetitive control cycles of controlling the multiple volume displacement elements. 
     
     
       13. The system as in  claim 12 ,
 wherein the controller controls each of the first volume displacement elements to prevent flow of fluid through the elastically deformable conduit at least once during each of the multiple repetitive control cycles; and 
 wherein the controller prevents each of the second volume displacement elements from occluding flow of the fluid through the elastically deformable conduit during an entirety of each of the multiple repetitive control cycles. 
 
     
     
       14. The system as in  claim 1 , wherein movement of the multiple volume displacement elements ensures that the input flow rate and the output flow rate are equal and constant during an entirety of each of the multiple repetitive control cycles of controlling the multiple volume displacement elements. 
     
     
       15. The system as in  claim 1 , wherein the input flow rate and the output flow rate are fixed and equal during an entirety of each of multiple repetitive control cycles of controlling the multiple volume displacement elements. 
     
     
       16. The system as in  claim 1 ,
 wherein the controller is operative to, during a segment of time of controlling the multiple volume displacement elements, move the first volume displacement element in a first direction and, prior to blocking flow of the fluid through the elastically deformable conduit, move the first volume displacement element in a second direction; and 
 wherein the second direction is opposite the first direction. 
 
     
     
       17. The system as in  claim 16 , wherein movement of the first volume displacement element in the first direction and the second direction equalizes the output flow rate to the input flow rate. 
     
     
       18. The system as in  claim 17 , wherein the controller is operative to, during the segment of time of controlling the multiple volume displacement elements, move the second volume displacement element from a first position of not blocking the fluid from flowing through the elastically deformable conduit and a second position of blocking the fluid from flowing through the elastically deformable conduit. 
     
     
       19. The system as in  claim 1 ,
 wherein the controller is operative to, during a segment of time of controlling the multiple volume displacement elements, move the first compensation displacement element in a first direction and then a second direction without blocking flow of fluid through the elastically deformable conduit, the second direction opposite the first direction; and 
 wherein the controller is operative to, during the segment of time of controlling the multiple volume displacement elements, control the second volume displacement element and the third volume displacement element at different times to block the fluid from passing through the elastically deformable conduit. 
 
     
     
       20. The system as in  claim 1 , wherein movement of the first volume displacement element during a first portion of a control cycle is from full occluding of the fluid from flowing to full non-occluding the fluid from flowing; and
 wherein movement of the third volume displacement element during the first portion of the control cycle is from fully non-occluding the fluid from flowing to fully occluding the fluid from flowing. 
 
     
     
       21. The system as in  claim 6 , wherein the opposite displacement directions include a first displacement direction and a second displacement direction, the second displacement direction being opposite the first displacement direction. 
     
     
       22. The system as in  claim 21 , wherein a net result of controlling movement of the first volume displacement element and the second volume displacement element includes outputting the output fluid at the desired flow rate from the output port. 
     
     
       23. The system as in  claim 1 ,
 wherein the first volume displacement element is operative to controllably occlude a first location of the elastically deformable conduit; 
 wherein the second volume displacement element is operative to controllably occlude a second location of the elastically deformable conduit; 
 wherein the third volume displacement element is operative to controllably occlude a third location of the elastically deformable conduit; 
 wherein the controller is operable to, while the second volume displacement element occludes fluid flow through the elastically deformable conduit at the first location, simultaneously control movement of: i) the first volume displacement element in a first direction towards decreased occlusion of the elastically deformable conduit at the first location, and ii) the third volume displacement element in a second direction towards increased occlusion of the elastically deformable conduit at the third location. 
 
     
     
       24. A method comprising: controlling first volume displacement elements to occlude an elastically deformable conduit at different places along the elastically deformable conduit during a fluid delivery cycle; during the fluid delivery cycle, controlling second volume displacement elements to volumetrically balance: i) an input flow rate of input fluid conveyed from a fluid source downstream into an input port of the elastically deformable conduit, and ii) an output flow rate of output fluid delivered from an output port of the elastically deformable conduit downstream to a recipient; wherein the output flow rate equals the input flow rate; wherein the first volume displacement elements include a first volume displacement element, a second volume displacement element, and a third volume displacement element; wherein the second volume displacement elements include a first compensation displacement element and a second compensation displacement element; wherein the second volume displacement element is disposed between the first volume displacement element and the third volume displacement element; wherein the first volume displacement elements are disposed between the first compensation displacement element and the second compensation displacement element; wherein the first compensation displacement element is disposed between the input port and the first volume displacement element; wherein the second compensation displacement element is disposed between the third volume displacement element and the output port, the method further comprising: controlling the first volume displacement elements to occlude fluid flow through the elastically deformable conduit at different times during a delivery cycle to deliver the output fluid downstream from the output port of the elastically deformable conduit to the recipient; and controlling the second volume displacement elements including the first compensation displacement element and the second compensation displacement element at multiple different non-blocking positional settings to provide fluid flow compensation for the first displacement elements. 
     
     
       25. The method as in  claim 24  further comprising:
 controlling the input flow rate and the output flow rate to be substantially constant and greater than zero. 
 
     
     
       26. The method as in  claim 24  further comprising:
 controlling movement of the first volume displacement elements and the second volume displacement elements to provide constant uni-directional flow of the output fluid to the recipient. 
 
     
     
       27. The method as in  claim 24 , wherein controlling the second volume displacement elements includes preventing a backflow of the input fluid received at the input of the elastically deformable fluid toward the fluid source. 
     
     
       28. The method as in  claim 24 ,
 further comprising:
 while the second volume displacement element occludes fluid flow through the elastically deformable conduit, controlling movement of the first volume displacement element to draw the input fluid downstream from the fluid source into the input of the elastically deformable conduit. 
 
 
     
     
       29. The method as in  claim 24  further comprising:
 while the second volume displacement element occludes fluid flow through the elastically deformable conduit, controlling movement of the first volume displacement element and the third volume displacement element in opposite directions to convey the output fluid downstream from the output of the elastically deformable conduit to the recipient at a desired flow rate. 
 
     
     
       30. The method as in  claim 24 
 further comprising: while the second volume displacement element occludes fluid flow through the elastically deformable conduit: i) controlling movement of the third volume displacement element to convey the output fluid downstream from the output of the elastically deformable conduit to the recipient, and ii) controlling movement of the first volume displacement element to draw the input fluid downstream from the fluid source into the input of the elastically deformable conduit. 
 
     
     
       31. The method as in  claim 24  further comprising:
 controlling the second volume displacement elements to provide fluid flow compensation to volumetrically balance the input flow rate and the output flow rate. 
 
     
     
       32. The method as in  claim 24 , wherein the fluid source is a first chamber of a diaphragm pump, the method further comprising:
 measuring a volume of a second chamber of the diaphragm pump to determine the output flow rate. 
 
     
     
       33. A system comprising:
 an elastically deformable conduit; 
 multiple volume displacement elements to contact the elastically deformable conduit and displace fluid in the elastically deformable conduit, the multiple volume displacement elements disposed between an input port and an output port of the elastically deformable conduit; and 
 a controller to control movement of the multiple volume displacement elements, the controller volumetrically balancing: i) an input flow rate of input fluid conveyed from a fluid source into the input port of the elastically deformable conduit, and ii) an output flow rate of output fluid delivered from the output port of the elastically deformable conduit to a recipient; and 
 wherein the controlled movement equalizes the output flow rate and the input flow rate; 
 wherein the multiple volume displacement elements controlled by the controller include: first displacement elements and second displacement elements disposed between the input port and the output port; 
 wherein second displacement elements include a first compensation displacement element and a second compensation displacement element; 
 wherein the first displacement elements include a first volume displacement element, a second volume displacement element, and a third volume displacement element; and 
 wherein the second volume displacement element is disposed between the first volume displacement element and the third volume displacement element; 
 wherein the first displacement elements are disposed between the first compensation displacement element and the second compensation displacement element; 
 wherein the first compensation displacement element is disposed between the input port and the first volume displacement element; and 
 wherein the second compensation displacement element is disposed between the third volume displacement element and the output port; and 
 wherein the controller is operative to: 
 for a first portion of a control cycle: i) control the second volume displacement element to completely block flow of the fluid; ii) control movement of the first compensation displacement element to compensate movement of the first volume displacement element; iii) control movement of the second compensation displacement element to compensate movement of the third volume displacement element such that the input flow rate of input fluid conveyed from a fluid source into the input port of the elastically deformable conduit is equal to the output flow rate of output fluid delivered from the output port of the elastically deformable conduit to a recipient.